Firearm



Apri l14, 193e.

F. F. BURTON FIREARM 5 sheets-sheetV 1 Filed Dec.

V/////////////////////////////////////////////////l/A April 14, 1936. F.F. BURTON FIREARM 5 Sheets-Sheet 3 Filed Dec. 19, 1933 April 14, 1936.

F. E. BURTON FREARM 5 Sheets-Sheet 4 Filed 4Dec. y \l9, 1935 F. F.BURTON April 14, 1936.

" FIREARMH Filed Dc. 19, 1933 5 sheets-sheet 5 @gli Patented Apr. 14, .1936 UNITED STATES' PATENT OFFICE FIREARM u Application December 19,1933, Serial No.v 703,035 18 lClaims. (Cl. 42-69)` This inventionrelates to an improvementl in firearms and has for one of its objectsthe provision of superior means for guarding against the accidentaldischarge of the arm. l

Another object of the present invention is to provide a simple, reliableand effective firearm construction wherein the movement of the triggeritself automatically eiects the locking of the sear when rearward draftis released from the trigger.

Another object is to provide a mechanism suitable for the class offirearms commonly known as semi-automatic, which will eiectively guardagainst the unintentional iiring of a second shot after the arm has beenautomatically reloaded.

A still further object is to provide superior means whereby the releaseof the firing-pin or other firing member of the arm is automaticallyguarded against when the breech-bolt is in other than its fully-closedposition. v

Other objects and advantages will appear to those Skilled in the artfrom the following, considered in conjunction with the accompanyingdrawings and the appended claims.

In the accompanying drawings:

Fig. 1 is a broken view in side elevation of one form which a firearmembodying the present invention may assume, with a portion of theframe-cover broken away;

3o Fig. 2 is a similar view on an enlarged scale but with certain of theparts shown in vertical central section and the firearm being shown ascocked preparatory to firing;

Fig. 3 is a view corresponding to Fig. 2 but showing the eiect of theinitial sear-unlocking movement of the trigger; l

Fig. 4 isa similar but less comprehensive view, showing the positionswhich the parts assume at the instant the arm is fired;

Fig. 5 is a view to Fig. 3 but showing tached;

Fig. 10 is a similar view ofthe transmittingmember detached; A

Fig. 11 is a view partly in side elevation and 55 partly in verticalsection corresponding to Fig. 2

but showing another form which the present invention may assume;

Fig. 12 is a perspective View of the ysear of the rearm shown in Fig.11;

Fig. 13 is a view partly in side elevation and l 5 partly in verticallongitudinal section of still another form which a rearm may assume` inaccordance with the present invention, the arm being shown as cocked;

Fig. 14 is a similar view showing the positions 10 which the partsassume after the gun has been red and after the breech-bolt has startedits rearward travel;

Fig. 15 is a similar view but showing the positions'which the partsassume after the gun has 15 been fullycocked, the boltjhas been returnedto its fully-closed positionthe trigger still being held in its rearwardposition;

Fig. 16 'is a top or plan view of the frame-'portion of the firearm andthe portion of the butt- 20 stock upon which the same is mounted, thepivotal hammer being shown partly in horizontal section; v

Fig. 17 is a transverse sectional view taken on the line l'L-I'l of Fig.13; 25

Fig. 18 is a perspective view of the trigger of the rearm of Figs. 12 etseq.;

Fig. 19 is a similar view of the sear detached; and

Fig. 20 is a similar view of the transmitting- 30 member detached. l

The embodiment of the present invention herein chosen for illustrationin Figs. 1 to 10 inclusive includes a frame 20 having amechanism-receiving chamber 2l therein which opens laterally 35 on oneside, as clearly indicated -in Figs. 5 and 6. The said frame is providedwith a usual triggerguard 22 and is secured tothe forward end of abutt-stock 23.

Fitting over the'frame 20 above referred to is 40 a frame-cover 24 ofinverted 4U-shaped form in cross-sectionand having attached to itsforward .end the usual barrel 25 and forestock 26'. n

28. 'I'he said spring ,36 encircles the reduced'for- |50` ward end ofa'guide-rod 32 and bears against an abutment-shoulder 33 formed thereon.The rear end of the said guide-rod 32 is seated, as shown, in a shallowsocket 34 in the rear wall of the mechanism-receiving chamber 2| of theframe 20. 65

In its under face the firing-pin 23 is formed with a sean-notch 35, therear wall of which is engaged in the usual manner by a senr-nose 33forming a feature of a sear 31 mounted within the chamber 2| of theframe 20 upona pin 33 extending transversely across the said chamber.

'I'he said sear is urged in the direction required under face of a lug42 laterally offsetting from a plate-like member 43 which forconvenience of description may be designated as a transmitting-member."'Ihe said spring 43 exerts a constant -eiort to move the saidtransmitting-member forwardly and to rock the same about the pin 33.

The transmitting-member 43 just above referred to is provided with aforwardly-and-upwardly-inclined guide-slot 44 through which extends thepin 33 mounting the sear 31 as previously described.

intersecting at the rear end,

The forwardupper end of the transmittingmember 43 is rounded, as shown,to provide a cam-surface 4I adapted to be enased on occasion by arearwardly-and-upwardly-inclined transmitting-member actuating-surface43 formed in the rear end of the breech-bolt 21 before referred to. Thecam-surface 4I is abo engaged, for being held in its depressed positionby a longitudinal holding-surface 43l formed onthe underside of the saidbreech-bolt and the actuating-surface 46. 'I'he rear shank-like portion41 of the said transmitting-member 43 extends beneath a guide-lug 43offsetting from the sear 31 and terminates in what may be suitablytermed a transmitting-head 49. The under surface of -thetransmitting-head 49 normally rests upon a thrust-receiving abutment 53constituting the upper surface of a lug 5I laterally oifsetting vfromthe sear 31'adjaoent referred to.

The transmitting-head 49 of the transmittingmember 43 also has itsforward face I2 upwardly-and-rearwardly-sloped, a's shown. for cam-likecoaction with a retaining-abutment I3 fol-med upon a trigger. having ausual finger-piece II and mountedfoi rocking movement upon a pin I3extending transversely through the frame 23. The-said trigger I4 isurged in a-direction required to move itsilnger-piece II forwardly by atrigger-spring, the forward end of which is seated'against the bottom ofa spring-pocket I3 formedintherearedgeofthesaidtriggeru.

The retaining-abutment I3 previously referred to of the trigger I4 isintersected by a scar-actuating abutment I3 extending at a substantialright angle with respect thereto and normally voverlying the upper edgeof the transmittinghead 43 of the iransmitting-member 43.

The trigger I4 -is also provided with a for'-'wardly-and-upwardly-sloping scar-locking `fin ger 33, the outer end ofwhich'constitutes a scar locking' abutment Il coacting -on occasion witha locking-abutment 32 formed by the lower rear corner of the overhangingmm of the scar nose 33 of the sear 31.

For the4 Purpose of insuring the movement of the secr-locking abutmentIl ofA the trger I4 the guide-lug 43 previously time, held in itsdepressed position by the user.

of the arm, when the breech-bolt 21 Vis moved rearwardly, the camvsurface I2l thereof will engage the cam-surface 32b oi.' the trigger 54and depress the latter for the purpose above referred to.

Let it be presumed that the parts of the firearm are in the positions inwhich they are shown in Figs. 1 .and 2 and that a cartridge is in placein the cartridge-chamber-of the barrel .25. It will be seen by referenceto the figures referred to that the scar-locking abutment 3| of thetrigger I4 is interposed in the path of the locking-abutment 32 of thesear 31, so that the Sear-nose 33 cannot be withdrawn from the searnotch35 of the firing-pin. 23. Thus, the rearm is guarded against accidentaldischarge until such time as the trigger is intentionally operated, aswill be presently described.

Let it now be assumed that it is desired to release the ringpin 23for'ring the arm. For,

this IJUIDOse, rearward manual pressure will be exerted upon thefinger-piece I5 of the trigger 54, with the eiect of first swinging thesearlocking abutment 6l of the trigger I4 downwardly and forwardly outof the path of the locking-abutment 32' of the sear 31, as shown in Fig.3 of the drawings. During the swinging movement of-the trigger for thepurpose :lust

referred to, the scar-actuating abutment I3 of the said trigger willmove toward the upper face of the transmitting-head 43 of thetransmitting- .member 43, but will not engage therewith, ow-

ing .tothe lost motion provided for, until vauch 'time as thescar-locking abutment 3| is smmg clear-or substantially clearof the pathof the locking-abutment 3 2 of the sear 31, also askinf dlcated in Fig.3.

A continued rearward draft upon the finger? piece II of the trigger I4will cause'thesearactuating abutment I3 ofthe trigger I4 to exertadownward thrust upon the transmitting-head 43 of the member 43, whichthrust will be-transmitted thereby to the upwardly-facingthrustreceiving abutment Il 'of the scar 31, upon which the under faceof the said' transmitting-head 43 normally rests. Thisemoveme'nt willeffect the swinging of both the transmitting-member 43 and the sear 31about the pin 33 as a center,-

with the eifect of ultimately dlsengaging the scar-nose 33 of the saidsear from the scar-notch 35 of the firing-pin 23, whereupon the-saidtiring'- pin will be released for rapid forward travel under the urge ofits spring 33 to effect the firing of the cartridge in thecartridge-chamber of the barrel 2I.I Fig. 4 represents the positionswhichthe parts assume at the-instante! firing.

The nrearm having been discharged, thenext normal step in the operationof the same would be the retraction lof the breech-bolt 21, whichvretraction may be effected automatically, as in some types of automaticand semi-automatic nrearms, of the character shown in Figs. 1 to 10inclusive, or manually. as for instance in the localled-slide-actiontype of firearm.l

The initial rearward movement of the breechbolt 21 causes the inclinedactuating-surface 46 thereof to engage the cam-surface 45 at the upperforward end of the transmitting-member 43, with the effect, as the boltcontinues its rearward movement, of imparting a combined rockingmovement and rearward bodily movement to the said transmitting-member 43against the tension of the spring 40.

The movement of the transmitting-member 43 as just above describedserves to shift the transmitting-head 49 thereof rearwardly out of linewith the Sear-actuating abutment 59 of the trigger 54, therebypermitting the sear 31 to swing upwardly under the urge of thesearspring 31a so as to locate its Sear-nose 36 in position `forreengagement with the scar-notch 35 of the firing-pin 2B. Thedownwardly-facing holding-surface 46a of the breech-bolt 21 now servesto hold the transmitting-member l43 inv the position described untilsuch time as said rbreech-bolt has been substantially restored to itsfully closed position as indicated in Figs. 1 and 2.

The upward swinging movement of the sear 31 as just described carrieswith it the rear end of the transmitting-member 43, which at this timeis resting upon the thrust-receiving abutment B of the said sear, andthus shifts the upwardly-and-rearwardly-sloping forward face 52 of thetransmitting-head 49 into position for engagement with theretaining-abutment 53. of the trigger 54. The parts will now haveassumed the positions in which they are shown in Fig. 5.

In the event that, during the rearward travel of the breech-bolt 21 asabove described, the trigger 54 is not at the time held in its depressedposition by the user of the arm, the cam-surface 62B of the breech-bolt21 will engage with the cam-surface 62b of the trigger 54 and effect thedepression of the latter. Thereafter, until the breech-bolt 21 has beenrestored substantially to its forward position, the under surface of thesaid breech-bolt will retain the said trigger in its depressed position,to thus insure the continued displacement of the locking-abutment SI ofthe said trigger out of the path of the locking-abutment 52 of the sear31.

After the breech-bolt 21 has completed its rearward travel and has againbeen moved forwardly into its substantially-fully-closed position, thedownwardly-facing holding-surface 46 and the actuating-surface 46 of thesaid breech-bolt will have moved clear of the cam-surface 45 of thetransmitting-member 43. The trigger-depressing cam-surface 52a will atthe same time have been moved forwardly entirelyclear of the camsurfaceB2b ofthe trigger 54 to thus permit the said trigger to swing forwardlyyunder the urge of the trigger-spring 51 as soon as the user of the armhas released manual rearward draftV thereon.

Upon the forward movementnof the breechboltas described and theconsequent release of y the transmitting-member 43, the latter, underswing the said trigger and move the retainingabutment 53 upwardly to asuflicient degree to permit the said transmitting-head 49 to slip underthe abutment 59 and complete its forward movement so as to be restoredto the position in v which it is shown in Figs. l and 2.

The release of rearward pressure upony the flngerapiece 55 of thetrigger 54 and the consc-v quent swinging movement of the said triggerunder the urge of its spring 51, as just described,

' will again restore the sear-locking abutment 6l to its normal-positionin which it lies in the path of movement of the locking-abutment 62, ofthe sear 31 to thus again guard against the accidental release of thefiring-pin 28 until such time as the trigger has been intentionallyoperated.

In the rearm shown in Figs. -11 and 12, no so-called transmitting-memberis employed to transmit the movement of the trigger to the sear, but adirect actuation of the latter by the said trigger is provided for, aswill be presently described.

In the construction shown in the figures referred.- to, a-pivotal sear63 is employed which is provided with a Sear-nose 64 engageable with ascar-notch 65 formed in Athe under face of a firing-pin 66 correspondingsubstantially to the firing-pin 28 before described. The said sear B3 isalso provided with a locking-abutmentl 61 engageable on occasion by aISear-locking abutment 68 constituting the upper outer face of asearlocking finger 69 upwardly-and-forwardly-extending from a triggerpivotally mounted upon a pin 1i and having an integral finger-piece 12urged forwardly by a trigger-spring 13.

'I'he trigger 10 is also provided with a downwardly-facingSear-actuating abutment 14 overlying a thrust-receiving finger forming arearward extension of'the sear 63 before referred to. The said sear G3is urged in a direction required to enter its Sear-nose 64 into theSear-notch 65 of the firing-pin 56 by a helical spring 16, the

upper end of which is seated in a spring-pocket 11 opening out of thelower edge of the said sear. 'l

When the finger-piece 12 of the trigger 10 is drawn rearwardly, theSear-locking abutment 68 thereof will be swung forwardly and downwardlyclear of the locking-abutment 61 of the sear 63. When in the operationof the trigger the said Sear-locking abutment 68 has been lmoved clearorsubstantially clear-#of theA lockingabutment-61, the Sear-actuatingabutment 14 of the said trigger will engage with the upper face of thefinger 15 of the said sear and by a further movement of the trigger 10,the sear 53 will be swung to disengage its scar-nose .64 from theseat-notch 65 of the firing-pin 66 to release the latter and effect thefiring of the arm.

`When the firing-pin 664s retired rearwardly, preparatory to beingcocked the instant the rear wall of the Sear-notch 65 thereof ridesclear of the rear end of the Sear-nose 64 of the sear 63, `the spring 16will act to reenter the said searnose 64 into the Sear-notch 65,provided, of

course, that the rearward draft upon the ringerpiece 12-hasbeenfpreviouslyreleased. Thus, as in the construction of Figs. 1 to l0inclusive, the trigger itself is provided with means for dev nitelylocking the sear against accidental release In this constructionverse'pin 18 and acts strike the rear end of a firing-pin 88 mounted ina reciprocating breechbolt 88*. The striking action of the hammer 18 iseffected under the urge of a hammer-spring lj 8| which encircles aguide-rod 82 pivotally coupled at its. rear end by means of a pin 83 tothe yhammer 18 and provided with a forwardlyfacing spring-abutment 84against which the which the forward end of the guide-rod 82 rides.

` The hammer 18 is also provided with a searnotch 81 receiving aSear-nose 88 forwardlyextending from a sear 88 pivotally mounted upon atransverse pin 88.' The said sear 88 is urged in a direction required toengage its scar-nose 88 with the Sear-notch 81 by a spring 8| lhousedmainly within a spring-pocket 82 formed in a trigger 88 pivotallymounted upon 'the pin 88 before referred to.

The trigger 88 is formed in its upper and forward edges with alongitudinal channel 84 receiving, with freedom for relative rockingmovement, the sear 88 before referred to. The said trigger 88 alsoincludes a usual finger-piece 85, which latter is urged forwardly by aU-shaped triggerspring 88, as clearly shown in Figs. 13 and 14.

For effecting the operation of the sear 88 by means of the trigger 88,the said trigger is provided. with an upwardly-facing saar-actuatingabutment 81 normally overlain by a transmittingfinger 88 laterallyoffsetting from a sheet-metal transmitting-member 88. The saidtransmittingmember 88 is provided at its forward end with alaterally-osetting guide-flange |88 loosely fitting in aforwardly-and-upwardly-sloping transverse guide-notch 8| formedin theframe |82 of the The transmitting-member 88 is also formed with a tongue|88 extending into a spring-pocket |88 formed in the frame |82andengaging the outer end of a spring |85, which latter exerts aconstant enort to concurrently move the transmitting-member 88 bodilyforwardly and the forward portion thereof upwardly.v

e The transmitting-finger 88 of the member 88 normally overlies theabutment 81 of the trigger 88 and is itself normally overlain by .athrustreceiving abutment |88 forming the under face of an arm |81rearwardly extending from the sear 88. The under face of the breech-bolt88* constitutes a holding-surface |88 for holding thetransmitting-member 88 in its inoperative position, as will behereinafter described. sloping rearwardly and upwardly from theholding-surface |88 of the said breech-bolt is fa'ce |88.

When the breech-bolt is in its fully-closed position and the armiscocked as indicated in Fig. 13, the transmitting-nger 88 of thetransmittinga cam-like actuating-surmember 88 is interposed betweentheupwardlyfacing scar-actuating abutment 81 vof the trigger bolt 88* bemoved vrearwardly for re-,loading and re-cocking, the slopingactuating-surfacevl88 of the said breech-bolt will engage the forwardend of the transmitting-member 88 and shift the same rearwardly towithdraw the transmitting-finger "88 thereof out fromunder thethrust-receiving abutment |88 of the sear 88. 'I'he movement justdescribed frees the sear 88 from the control of the trigger 88 andpermits the spring 8| to reengage the Sear-nose 88 with the Sear-notch81 of the hammer 18 when the latter has been swung into itsfully-retired position as a result of the rearward travel of thebreech-bolt.

After the disengagement of the nger 88 has i been eifected as labovedescribed, the holding-surface |88 of the breech-bolt 88* serves to holdthe said fingerv in such disengaged position until the said breech-boltis again restored to its forward and substantially-fully-closedposition, at which time both of the surfaces |88 and |88 thereof willride clear of the forward end of the transmittingmember 88. I

The clearing of the forward end of the transmitting-member v88 by thecomplementary surfaces of the breech-bolt 88* as above described willpermit the spring |85 to move the said transmitting-member 88 forwardly,and in the event that the rearward draft upon the trigger 88 has Anot asyet been released, the forward edge of the transmitting-finger 88 willengage with the rear surface of vthe arm |81 of the sear 88, and willthus be prevented in effect from re-coupling the trigger and sear. Uponthe release of the trigger 88, the spring l|85 will-be free to act tointerpose the transmitting-finger 88 of the member 88 between therespective abutments 81 and |88, pre-j paratory to another cycle ofoperation of thol rearm. l

As thus constructed, the trigger 88 and sear 88 are in eectuncoupledfrom each other when the breech-bolt 88*L is in any other thanits closed, or substantially-closed, position, thus guarding against theaccidentalflring of a second shot.

The invention may be carried out in other specific ways than thoseherein set forth without departing from the spirit and essentialcharacter-- istics of the inventionI and the present embodiv `ments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein. t

I claim: I

1. In a firearm, the combination with a trigger; of a sear movableindependently of the said tris" ger; and sear-loclgigneans movable intoitsunloclring position by the said trigger itself and acting to preventthe accidental releasing-movement of the said sear when the said triggeris in its normal position.

2. In a firearm, the combination with a trigger;

of a sear movable -independently of the said trigger; andv scar-lockingmeans carried by and movable into its unlocking pomtionby the saidtrigger itself and acting to prevent the accidental releas-Iing-movement of the said sear when the said trig- V ger is in its normalposition.

3. In a firearm, the combination with the ing means movable by the saidtrigger andacting to prevent the accidental releasing-movement of thesaid sear when the said trigger is in its normalposition; d meansmovable by the said breechbolt and ting to retire the said.seat-locking: means. f

4. In a traum, the combination' 'with the' ademas' releasing-movement ofthe said sear when the i said trigger is in its normal'position; andmeans movable by the said breech-bolt and acting to Aretire the saidSear-locking means. Y

5. In a. firearm, the combination with the breech-bolt, trigger and searthereof; of searlocking means movableby the said trigger and acting toprevent the accidental releasing-movement of the said sear when the saidtrigger is in its normal position; and means carried by and movable withthe said breech-bolt and acting t0 retire the said Sear-locking means.

6. In a firearm, the combination with thel said sear and movabletherewith; and a second locking-abutment movable by the said triggerinto the path of movement of the said first lockingvabutment to guardagainst the unintentional release of the said sear when the said triggeris in its normal position.

8, In a iirearm, the combination with a trigger; of a sear movableindependently of the said trigger; a nrst locking-abutment carried bythe said sear and movable therewith; and a'second lock-` ing-abutmentcarried by and movable with the said triggerl into the path of movementof the 4said nist locking-abutment to guard against the unintentionalrelease of the said sear when thesaid trigger isin its normal position.

9. In a rearm, the combination with the trigger` and sear thereof; of afirst locking-abutment carried by the saidsear and movable therewith;

45 anda secondlocking-abutment carried'by the 60 release or the seidSear when the said trigger is j said trigger and movable thereby intothe path of movement of the said rst locking-abutment to guard againstthe unintentional release of the said sear when the said trigger is inits'normal 50 position; one of the. said locking-abutments off- '55een-led by 'and movable with the seid seaiandlaterally offsettingtherefrom; and a second locking-abutment movable by the `saidtrigger-itself into the path of movement ofthe said rst lock.

ing-abutment to guard against the unintentional in its'normal position.

11. In a iirearm,-thecombination with the breech-bolt, trigger and se'arthereof; of a `first locking-abutment carried by th'e' said sear; a sec-65 ond locking-abutment movable by the said trigger 70 said breech-boltforreting. the said second lockinto the pathof movement of thesai'dfirst locking-abutment to guard against the unintentional release-of thesaid sear when the said trigger is in its normal positlom'and meansmovable by the 12. a firearm, the combination with the breech-bolt,trigger and sear thereof; of a rst locking-abutment carried by the saidsear; a

second locking-abutment .movable by the said trigger into the path ofmovement of the said rst locking-abutment to guard against theunintentional release of the said sear' when the said trigger is in itsnormal position-: and means carried by and movable with the saidbreech-bolt for l retiring the said second locking-abutment.

13. In a rearm, the combination with the breech-bolt, trigger and searthereof; of a mov- Aable transmitting-member acting when in one positionto transmit the movement of the said trigger tothe said sear, andmovable into an inoperative position by means carried by and bodily'movable with the said breech-bolt.

1 4, In a rearm, the 'combination with the breech-bolt, trigger and searthereof; of a. movable transmitting-member acting when in one positionto transmit the movement of the saidy trigger to the said sear andmovable into an inoperative position by means carried by the saidbreech-bolt; spring-means normally urging the said transmitting-memberinto its operative position; and retaining-means. associated with thesaid trigger to releasably hold the said transmitting-member -in itsinoperative position.

15. In a rearm, the combination with the breech-bolt, trigger and searthereof; of a movable'transmitting-member acting Vwhenin one position totransmit the movement of the said trigger to the said sear and movableinto an inoperative position by means carried by the said breech-bolt;spring-means' normally urging the said transmitting-member into'itsoperative' pofsition; and a retaining-abutment carried by .the saidtrigger to releasably holdv the said trans-- mitting-member in itsinoperative position.

16. In a rearm, the combination with .the

breech-bolt, trigger and sear thereof; of a transmitting-member mountedwith capacity for combined rocking and bodily movement and acting whenin one position to transmit the movement of the said trigger to the saidsear and movable in a combined rocking and bodily movement-path into aninoperative position by means associated with the said breech-bolt.

17. In a firearm, the combination with the breech-bolt, trigger and searthereof; of a transmitting-member mounted with capacity for -combinedr'ocldng and bodily movement and acting when in one position to transmitthe movement of the said trigger t0 the Said Sear and movable in acombined rocking and lbodily movementpath intoan inoperative position bylmeans carrled by `and bodily movable with the said breechbolt.

18. In a firearm, the Acombination with the breech-bolt, trigger and-sear thereof; of a movable transmitting-member acting when in oneposition to transmit the mpvement or the 'said trigger tothe said searand movable -into an noperative position by means associated withthesaid breech-bolt; and spring-means seatingv against both the said searandthe said trans- :pitting-member and exerting an 'effort to move thesaidtransmitting-member into its operative

